Method for precipitating and separating SiO2 and TiO2 in titanium metallurgical molten salt chlorate slag by using air oxidation-physical method and application of method

Abstract

The invention belongs to the technical field of titanium metallurgy solid waste utilization, and relates to a method for precipitating and separating SiO2 and TiO2 in titanium metallurgy molten salt chlorate slag by utilizing an air oxidation-physical method and application of the method. According to the method, the low-valence silicon element in the molten salt chlorate slag solution is treated in an air oxidation mode; meanwhile, volatile components such as MnCl2, MnCl3, FeCl2, FeCl3, AlCl2, SiCl4 and the like in the molten salt chlorate slag solution are removed by utilizing the principle of concentration diffusion and differential pressure diffusion. Through the treatment process, the use amount of the curing agent required for removing CaCl2 and MgCl2 in the chemical curing process can be remarkably reduced, so that the cost of curing and regeneration of the waste salt is greatly reduced, and finally, comprehensive utilization of resources and quality and efficiency improvement of the industry are realized.

Description

Technical Field

[0001] The invention belongs to the technical field of titanium metallurgical solid waste utilization, and relates to a method for separating SiO2 and TiO2 in titanium metallurgical molten salt chloride slag by precipitation using an air oxidation-physical method and an application thereof. Background Art

[0002] Xinjiang is rich in vanadium-titanium magnetite resources, but the ore composition is complex, the grade is low (TiO2 <10%), and the calcium and magnesium content in the titanium ore is high (MgO + CaO ≥ 7%). The molten salt chlorination process is used to prepare titanium tetrachloride as a raw material for sponge titanium production, realizing the high added value conversion of titanium resources. Due to the composition of the titanium ore and the characteristics of the molten salt chlorination process, 20,000 tons of chloride slag will be produced each year (calculated based on 10% of the titanium tetrachloride output). For a titanium tetrachloride plant with an annual output of 200,000 tons of titanium tetrachloride, more than 20,000 tons of waste salt are discharged annually. In addition to NaCl, the solid waste also includes CaCl2, MgCl2, FeCl3, SiO2, SiCl4, AlCl3, etc. The main components of the waste salt are shown in Table 1:

[0003] Table 1 Chemical composition of titanium metallurgical molten salt chloride slag

[0004] NaCl <![CDATA[CaCl2]]> <![CDATA[MgCl2]]> <![CDATA[SiO2]]> <![CDATA[FeCl3]]> <![CDATA[MnCl2]]> <![CDATA[AlCl3]]> <![CDATA[SiCl4]]> 51.37 4.75 17.3 10.55 4.15 4.23 2.45 5.17

[0005] At present, the common disposal method adopted at home and abroad is filling cooling-crushing-lime mixing and landfilling in professional slag yards. More than 80% of its components are soluble metal chlorides. This treatment method is relatively extensive and no valuable components are recycled. Summary of the invention

[0006] The purpose of the present invention is to overcome the disadvantages of the prior art and to provide a method for separating SiO2 and TiO2 from titanium metallurgical molten salt chloride slag by precipitation using air oxidation-physical method and its application.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The invention discloses a method for separating SiO2 and TiO2 from titanium metallurgical molten salt chloride slag by precipitation using an air oxidation-physical method. The molten salt chloride slag solution contains MgCl2 and CaCl2, and the method comprises the following steps:

[0009] Step 1: a specified amount of molten salt chloride slag solution is kept warm for the first time at a first specific temperature, during which compressed air is introduced into the molten salt chloride slag solution to expel volatile components and allow SiO2 fine particles to nucleate, precipitate and grow on the surfaces of heterogeneous crystal nuclei of TiO2 particles and solid carbon particles to form SiO2 aggregate particles;

[0010] Step 2: heat-insulating the molten salt chloride slag solution for a second time at a second specific temperature to precipitate SiO2 polymer particles, and filtering the molten salt chloride slag solution to reduce the content of SiO2 polymer particles in the molten salt chloride slag solution;

[0011] Step 3: adding a curing agent to the molten salt chloride slag solution to remove MgCl2 and CaCl2;

[0012] Step 4: Separate the sodium chloride solution, SiO2 concentrate, TiO2 concentrate and coke powder particle raw materials by combining water dissolution method and gravity separation method.

[0013] Specifically, the present invention uses air oxidation to treat low-priced silicon elements in molten salt chloride slag solution; at the same time, by using the concentration diffusion and pressure diffusion principles, volatile components such as MnCl2, MnCl3, FeCl2, FeCl3, AlCl3, SiCl4, etc. in the molten salt chloride slag solution are eliminated. On this basis, with the help of heterogeneous nucleation, the fine SiO2 particles in the molten salt chloride slag solution are nucleated and gradually grow. Large-sized SiO2 particles will settle and stratify under the influence of density difference, and finally settle at the bottom of the salt tank. Such operation can lay the foundation for the subsequent development of chemical solidification and removal of CaCl2 and MgCl2 in waste salt. Through this treatment process, the amount of curing agent required to remove CaCl2 and MgCl2 in the chemical solidification process can be significantly reduced, thereby greatly reducing the cost of solidification and regeneration of waste salt, and ultimately achieving comprehensive utilization of resources and quality and efficiency improvement of the industry.

[0014] It should be noted that in step one: during the insulation period, compressed air is introduced into the molten salt chloride slag solution through a steel pipe, and the compressed air forms dispersed and evenly distributed bubbles in the molten salt chloride slag solution, and the volatile components in the molten salt chloride slag solution are absorbed by the principles of concentration diffusion and pressure diffusion. The volatile components include MnCl2, MnCl3, FeCl2, FeCl3, AlCl3, SiCl4 and a small amount of TiCl4, so that the volatile components are discharged with the air and enter the alkali solution absorption tank to absorb the volatile components; in step two: the salt solution is filtered through a 10ppi-400ppi ceramic plate, and the SiO2 content in the filtrate is reduced from more than 10% to less than 0.8%.

[0015] It should be noted that in the molten salt chloride slag solution, silicon in the form of divalent silicon or trivalent silicon oxide is combined with sodium, calcium, magnesium and other ions to form a liquid sol, which cannot be directly precipitated and separated. The oxygen component in the compressed air reacts with low-valent silicon to make low-valent silicon [SiO2] + 、[SiO] 2+Oxidized into fine SiO2, the fine SiO2 uses TiO2 and solid carbon particles as heterogeneous crystal nuclei, allowing SiO2 to nucleate, precipitate and grow on the surface of the heterogeneous crystal nuclei of TiO2 and solid carbon particles with higher melting points, forming SiO2 polymer particles, which are salt-containing SiO2.

[0016] Furthermore, in the step 1, the first specific temperature is 400° C. to 650° C., and the first insulation time is 0.5 h to 72 h.

[0017] Specifically, the first specific temperature can be 400℃, 450℃, 500℃, 550℃, 600℃, or 650℃, which can be adjusted according to time requirements; the first insulation time can be 0.5h, 10h, 20h, 30h, 40h, 50h, 60h, 70h, or 72h, which can be adjusted according to actual needs.

[0018] Furthermore, in the step 1, the air intake pressure of compressed air introduced into the molten salt chloride slag solution is 0.05Mpa-5Mpa, and the air intake time is 0.5h-72h.

[0019] The intake pressure can be 0.05Mpa, 1Mpa, 2Mpa, 3Mpa, 4Mpa, 5Mpa, which can be adjusted according to actual needs; the intake time can be 0.5h, 1h, 10h, 20h, 30h, 40h, 50h, 60h, 70h, 72h.

[0020] Furthermore, the volatile components in step 1 include MnCl2, MnCl3, FeCl2, FeCl3, AlCl3, SiCl4 and TiCl4.

[0021] Specifically, the separation method provided by the present invention utilizes compressed air to form dispersed and evenly distributed bubbles in the molten salt chloride slag solution, and absorbs volatile components in the molten salt chloride slag solution through the principles of concentration diffusion and pressure diffusion. The volatile components include MnCl2, MnCl3, FeCl2, FeCl3, AlCl3, SiCl4 and a small amount of TiCl4. The volatile components are discharged with the air and absorbed by the alkali solution absorption tank.

[0022] Furthermore, in the step 1, the specified amount of molten salt chloride slag solution is kept warm at a first specific temperature by first pouring the specified amount of molten salt chloride slag solution into a slag pot, and placing the slag pot into a heat preservation device for heat preservation.

[0023] Specifically, the molten salt chloride slag discharged from the chlorination furnace is measured by an electronic scale, a certain amount of the molten salt chloride slag is poured into a molten salt chloride slag insulation slag pot, and the slag pot is placed in the insulation furnace for insulation for a certain period of time.

[0024] Furthermore, the slag pot is made of carbon steel or stainless steel.

[0025] Specifically, the slag pot is made of one of Q235, Q245R, 310S or 1Cr18Ni9Ti; or, the furnace lining is made of a composite material of two of Q235, Q245R, 310S, 1Cr18Ni9Ti; or, the outer lining is made of one of the metal materials Q235, Q245R, 310S or 1Cr18Ni9Ti, and the inner lining is carbon bricks.

[0026] Furthermore, in the step 2, the second specific temperature is 700° C. to 930° C., and the second insulation time is 0.3 h to 5 h.

[0027] Furthermore, the curing agent is sodium sulfate, sodium aluminate, sodium silicate, sodium carbonate or sodium hydroxide.

[0028] Specifically, the curing agent can be a mixture of one or more of sodium sulfate, sodium aluminate, sodium silicate, sodium carbonate, and sodium hydroxide, and the specific selection can be made according to actual needs.

[0029] The present invention also provides a method for separating SiO2 and TiO2 from titanium metallurgical molten salt chloride slag by precipitation using air oxidation-physical method, and application of the method in separating chloride slag.

[0030] Specifically, SiO2, TiO2 and some coke powder particles are enriched in the filter residue, and sodium chloride solution, SiO2 concentrate, TiO2 concentrate and coke powder particle raw materials are obtained respectively through water-soluble and gravity separation. The sodium chloride solution is sent to chlor-alkali chemical industry, the SiO2 concentrate is used as refractory material or raw material for producing polysilicon, the TiO2 concentrate is returned to the chlorination furnace or used as raw material for sulfuric acid process titanium dioxide, and the coke powder particles are used as raw material for chlorination reducing agent.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. The present invention uses air oxidation to treat low-valent silicon elements in a molten salt chloride slag solution; at the same time, the principles of concentration diffusion and pressure diffusion are used to remove volatile components such as MnCl2, MnCl3, FeCl2, FeCl3, AlCl3, SiCl4, etc. in the molten salt chloride slag solution.

[0033] 2. The separation method provided by the present invention promotes the nucleation of fine SiO2 particles in the molten salt chloride slag solution by means of heterogeneous nucleation, and makes them grow gradually. Large-sized SiO2 particles will settle and stratify under the influence of density difference, and finally settle at the bottom of the salt tank, which is easy to separate, and can lay the foundation for the subsequent development of chemical solidification and removal of CaCl2 and MgCl2 in waste salt.

[0034] 3. The separation method provided by the present invention can significantly reduce the amount of curing agent required to remove CaCl2 and MgCl2 during the chemical curing process through this treatment process, thereby greatly reducing the cost of waste salt curing and regeneration, and ultimately achieving comprehensive utilization of resources and improving the quality and efficiency of the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, serve to explain the principles of the present invention.

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0037] Figure 1 The present invention is a schematic flow chart of the method for separating SiO2 and TiO2 in titanium metallurgical molten salt chloride slag. DETAILED DESCRIPTION

[0038] Here, exemplary embodiments will be described in detail, and the embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are only examples consistent with some aspects of the present invention described in detail in the appended claims.

[0039] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0040] like Figure 1 As shown, the present invention provides a method for separating SiO2 and TiO2 from titanium metallurgical molten salt chloride slag by precipitation using air oxidation-physical method, wherein the molten salt chloride slag solution contains MgCl2 and CaCl2, and specifically comprises the following steps:

[0041] Step 1: a specified amount of molten salt chloride slag solution is kept warm for the first time at a first specific temperature, during which compressed air is introduced into the molten salt chloride slag solution to expel volatile components and allow SiO2 fine particles to nucleate, precipitate and grow on the surfaces of heterogeneous crystal nuclei of TiO2 particles and solid carbon particles to form SiO2 aggregate particles;

[0042] Step 2: heat-insulating the molten salt chloride slag solution for a second time at a second specific temperature to precipitate SiO2 polymer particles, and filtering the molten salt chloride slag solution to reduce the content of SiO2 polymer particles in the molten salt chloride slag solution;

[0043] Step 3: adding a curing agent to the molten salt chloride slag solution to remove MgCl2 and CaCl2;

[0044] Step 4: Separate the sodium chloride solution, SiO2 concentrate, TiO2 concentrate and coke powder particle raw materials by combining water dissolution method and gravity separation method.

[0045] Example 1

[0046] This embodiment provides a method for separating SiO2 and TiO2 from titanium metallurgical molten salt chloride slag by precipitation using air oxidation-physical method, which specifically includes the following steps:

[0047] Step 1: a specified amount of molten salt chloride slag solution is kept warm for the first time at a first specific temperature, during which compressed air is introduced into the molten salt chloride slag solution to discharge volatile components and allow SiO2 to nucleate, precipitate and grow on the surface of the heterogeneous crystal nuclei of TiO2 and solid carbon particles;

[0048] Specifically, the molten salt chloride slag taken out from the chlorination furnace is measured by an electronic scale, and a certain amount of the molten salt chloride slag is poured into a slag pot, and then the slag pot is placed in a 400° C. insulation furnace for 72 hours;

[0049] During the insulation period, compressed air is introduced into the molten salt chloride slag solution through a steel pipe, the ventilation pressure is 0.05Mpa, and the ventilation time is 72h; the compressed air forms diffuse and uniformly distributed bubbles in the molten salt chloride slag solution, and absorbs the volatile components in the molten salt chloride slag solution through the concentration diffusion and pressure difference diffusion principles. The volatile components include MnCl2, MnCl3, FeCl2, FeCl3, AlCl3, SiCl4 and a small amount of TiCl4, so that the volatile components are discharged with the air and absorbed by the alkali solution absorption tank; the oxygen component in the compressed air is used to react with low-valent silicon to make low-valent silicon [SiO2] + 、[SiO] 2+ Oxidized into fine SiO2, the fine SiO2 uses TiO2 and solid carbon particles as heterogeneous crystal nuclei, allowing SiO2 to nucleate, precipitate and grow on the surface of the heterogeneous crystal nuclei of TiO2 and solid carbon particles with higher melting points;

[0050] Step 2: The molten salt chloride slag solution is kept warm for a second time at a second specific temperature to precipitate SiO2 particles, and the molten salt chloride slag solution is filtered to remove most of the SiO2 particles;

[0051] Specifically, after the heat preservation process is completed, the temperature of the molten salt chloride salt slag solution is raised to 700°C and kept warm for 5 hours. The viscosity of the molten salt chloride salt slag solution is reduced by heating, the growth of SiO2 particles is accelerated, and the large-sized SiO2 particles are accelerated to settle under the action of density difference, so that the solid-liquid stratification of SiO2 from the sodium chloride salt solution is achieved, and the SiO2 particles are deposited at the bottom of the slag tank;

[0052] The molten salt chloride slag solution was filtered through a 10ppi ceramic plate to reduce the SiO2 content in the filtrate from 10.5% to 0.8%.

[0053] Step 3: adding a curing agent to the molten salt chloride slag solution to remove MgCl2 and CaCl2;

[0054] As the raw material of regenerated salt to be treated, MgCl2 and CaCl2 are removed by adding a curing agent;

[0055] Step 4: Sodium chloride solution, SiO2 concentrate, TiO2 concentrate and coke powder particle raw materials are obtained by combining water-soluble and gravity separation.

[0056] Specifically, SiO2, TiO2 and part of coke powder particles are enriched in the filter residue, and sodium chloride solution, SiO2 concentrate, TiO2 concentrate and coke powder particle raw materials are obtained through water-soluble and gravity separation.

[0057] Example 2

[0058] This embodiment provides a method for separating SiO2 and TiO2 from titanium metallurgical molten salt chloride slag by precipitation using air oxidation-physical method, which specifically includes the following steps:

[0059] Step 1: a specified amount of molten salt chloride slag solution is kept warm for the first time at a first specific temperature, during which compressed air is introduced into the molten salt chloride slag solution to discharge volatile components and allow SiO2 to nucleate, precipitate and grow on the surface of the heterogeneous crystal nuclei of TiO2 and solid carbon particles;

[0060] Specifically, the molten salt chloride slag taken out from the chlorination furnace is measured by an electronic scale, and a certain amount of the molten salt chloride slag is poured into a slag pot, and then the slag pot is placed in a 650° C. insulation furnace for 0.5 h;

[0061] During the insulation period, compressed air is introduced into the molten salt chloride slag solution through a steel pipe, the ventilation pressure is 5Mpa, and the ventilation time is 0.5h; the compressed air forms diffuse and evenly distributed bubbles in the molten salt chloride slag solution, and absorbs the volatile components in the molten salt chloride slag solution through the concentration diffusion and pressure difference diffusion principles. The volatile components include MnCl2, MnCl3, FeCl2, FeCl3, AlCl3, SiCl4 and a small amount of TiCl4, so that the volatile components are discharged with the air and absorbed by the alkali solution absorption tank; the oxygen component in the compressed air is used to react with low-valent silicon to make low-valent silicon [SiO2] + 、[SiO] 2+ Oxidized into fine SiO2, the fine SiO2 uses TiO2 and solid carbon particles as heterogeneous crystal nuclei, allowing SiO2 to nucleate, precipitate and grow on the surface of the TiO2 and solid carbon particles with higher melting points;

[0062] Step 2: The molten salt chloride slag solution is kept warm for a second time at a second specific temperature to precipitate SiO2 particles, and the molten salt chloride slag solution is filtered to remove most of the SiO2 particles;

[0063] Specifically, after the heat preservation process is completed, the temperature of the molten salt chloride salt slag solution is raised to 930° C. and kept warm for 0.3 h. The viscosity of the molten salt chloride salt slag solution is reduced by heating, the growth of SiO2 particles is accelerated, and the large-sized SiO2 particles are accelerated to settle under the action of density difference, so that the solid-liquid stratification of SiO2 from the sodium chloride salt solution is realized, and the SiO2 particles are deposited at the bottom of the slag tank;

[0064] The molten salt chloride slag solution was filtered through a 400ppi ceramic plate to reduce the SiO2 content in the filtrate from 13.9% to 0.89%.

[0065] Step 3: adding a curing agent to the molten salt chloride slag solution to remove MgCl2 and CaCl2;

[0066] As the raw material of regenerated salt to be treated, MgCl2 and CaCl2 are removed by adding a curing agent;

[0067] Step 4: Sodium chloride solution, SiO2 concentrate, TiO2 concentrate and coke powder particle raw materials are obtained by combining water-soluble and gravity separation.

[0068] Specifically, SiO2, TiO2 and part of coke powder particles are enriched in the filter residue, and sodium chloride solution, SiO2 concentrate, TiO2 concentrate and coke powder particle raw materials are obtained through water-soluble and gravity separation.

[0069] Example 3

[0070] This embodiment provides a method for separating SiO2 and TiO2 from titanium metallurgical molten salt chloride slag by precipitation using air oxidation-physical method, which specifically includes the following steps:

[0071] Step 1: a specified amount of molten salt chloride slag solution is kept warm for the first time at a first specific temperature, during which compressed air is introduced into the molten salt chloride slag solution to discharge volatile components and allow SiO2 to nucleate, precipitate and grow on the surface of the heterogeneous crystal nuclei of TiO2 and solid carbon particles;

[0072] Specifically, the molten salt chloride slag taken out from the chlorination furnace is measured by an electronic scale, and a certain amount of the molten salt chloride slag is poured into a slag pot, and then the slag pot is placed in a 525° C. insulation furnace for 36 hours;

[0073] During the insulation period, compressed air is introduced into the molten salt chloride slag solution through a steel pipe, the ventilation pressure is 2.5Mpa, and the ventilation time is 31h; the compressed air forms diffuse and evenly distributed bubbles in the molten salt chloride slag solution, and absorbs the volatile components in the molten salt chloride slag solution through the concentration diffusion and pressure difference diffusion principles. The volatile components include MnCl2, MnCl3, FeCl2, FeCl3, AlCl3, SiCl4 and a small amount of TiCl4, so that the volatile components are discharged with the air and absorbed by the alkali solution absorption tank; the oxygen component in the compressed air is used to react with low-valent silicon to make low-valent silicon [SiO2] + 、[SiO] 2+ Oxidized into fine SiO2, the fine SiO2 uses TiO2 and solid carbon particles as heterogeneous crystal nuclei, allowing SiO2 to nucleate, precipitate and grow on the surface of the heterogeneous crystal nuclei of TiO2 and solid carbon particles with higher melting points;

[0074] Step 2: The molten salt chloride slag solution is kept warm for a second time at a second specific temperature to precipitate SiO2 particles, and the molten salt chloride slag solution is filtered to remove most of the SiO2 particles;

[0075] Specifically, after the insulation process is completed, the temperature of the molten salt chloride salt slag solution is raised to 815°C and kept warm for 2.3 hours. The viscosity of the molten salt chloride salt slag solution is reduced by heating, the growth of SiO2 particles is accelerated, and the large-sized SiO2 particles are accelerated to settle under the action of density difference, so that the solid-liquid stratification of SiO2 from the sodium chloride salt solution is achieved, and the SiO2 particles are deposited at the bottom of the slag tank;

[0076] The molten salt chloride slag solution was filtered through a 10ppi ceramic plate to reduce the SiO2 content in the filtrate from 12.4% to 0.72%.

[0077] Step 3: adding a curing agent to the molten salt chloride slag solution to remove MgCl2 and CaCl2;

[0078] As the raw material of regenerated salt to be treated, MgCl2 and CaCl2 are removed by adding a curing agent;

[0079] Step 4: Sodium chloride solution, SiO2 concentrate, TiO2 concentrate and coke powder particle raw materials are obtained by combining water-soluble and gravity separation.

[0080] Specifically, SiO2, TiO2 and part of coke powder particles are enriched in the filter residue, and sodium chloride solution, SiO2 concentrate, TiO2 concentrate and coke powder particle raw materials are obtained through water-soluble and gravity separation.

[0081] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0082] It should be understood that the present invention is not limited to what has been described above and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for separating SiO2 and TiO2 from titanium metallurgical molten salt chloride slag by air oxidation-physical precipitation, wherein the molten salt chloride slag solution contains MgCl2 and CaCl2, characterized in that: The specific steps include: Step 1: a specified amount of molten salt chloride slag solution is kept warm for the first time at a first specific temperature, during which compressed air is introduced into the molten salt chloride slag solution to expel volatile components and allow SiO2 fine particles to nucleate, precipitate and grow on the surfaces of heterogeneous crystal nuclei of TiO2 particles and solid carbon particles to form SiO2 aggregate particles; Step 2: heat-insulating the molten salt chloride slag solution for a second time at a second specific temperature to precipitate SiO2 polymer particles, and filtering the molten salt chloride slag solution to reduce the content of SiO2 polymer particles in the molten salt chloride slag solution; Step 3: adding a curing agent to the molten salt chloride slag solution to remove MgCl2 and CaCl2; Step 4: Separate the sodium chloride solution, SiO2 concentrate, TiO2 concentrate and coke powder particle raw materials by combining water dissolution method and gravity separation method.

2. The method for separating SiO2 and TiO2 from titanium metallurgical molten salt chloride slag by air oxidation-physical precipitation according to claim 1, characterized in that: In the step 1, the first specific temperature is 400° C. to 650° C., and the first insulation time is 0.5 h to 72 h.

3. The method for separating SiO2 and TiO2 from titanium metallurgical molten salt chloride slag by air oxidation-physical precipitation according to claim 1, characterized in that: In the step 1, the air intake pressure of compressed air introduced into the molten salt chloride slag solution is 0.05Mpa-5Mpa, and the air intake time is 0.5h-72h.

4. The method for separating SiO2 and TiO2 from titanium metallurgical molten salt chloride slag by air oxidation-physical precipitation according to claim 1, characterized in that: The volatile components in step 1 include MnCl2, MnCl3, FeCl2, FeCl3, AlCl3, SiCl4 and TiCl4.

5. The method for separating SiO2 and TiO2 from titanium metallurgical molten salt chloride slag by air oxidation-physical precipitation according to claim 1, characterized in that: In the step 1, the specified amount of molten salt chloride slag solution is kept warm at the first specific temperature by first pouring the specified amount of molten salt chloride slag solution into a slag pot, and placing the slag pot into a heat preservation device for heat preservation.

6. The method for separating SiO2 and TiO2 from titanium metallurgical molten salt chloride slag by air oxidation-physical precipitation according to claim 5, characterized in that: The slag pot is made of carbon steel or stainless steel.

7. The method of separating SiO2 and TiO2 from titanium metallurgical molten salt chloride slag by air oxidation-physical precipitation according to claim 1, characterized in that: In the step 2, the second specific temperature is 700° C. to 930° C., and the second insulation time is 0.3 h to 5 h.

8. The method for separating SiO2 and TiO2 from titanium metallurgical molten salt chloride slag by air oxidation-physical precipitation according to claim 1, characterized in that: The curing agent in step three is sodium sulfate, sodium aluminate, sodium silicate, sodium carbonate or sodium hydroxide.

9. Use of the method for separating SiO2 and TiO2 from chloride slag of titanium metallurgical molten salt by air oxidation-physical precipitation as described in any one of claims 1 to 8 in separating chloride slag.

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